Harriet Sergeant isn't the obvious candidate to write a sympathetic book about gangs in south London. A Daily Mail journalist and writer of reports for a "right of centre" thinktank, she is called out on her "Princess Di background" by her fixer, Swagger, early on in this book. Her interest in a group of criminally minded teenagers she meets outside a fried chicken takeaway is not, however, motivated by the desire to indulge in head-shaking. As her relationship with these "lost boys", failed by schools, parents and the care system, deepens, so does her rage and empathy. For all the detail of prisons and hostels, there is a sentimental streak running through the book. Sergeant compares Tuggy Tug and his compadres with her own privileged teenage son. While the book allows Sergeant to underline some of her most deeply held opinions  "If society wants youth to share its beliefs then it has to have the confidence to articulate those values with authority"  it also shows how her perceptions slowly shift. But she never makes it all about her: for once, these boys are front and centre.